Calcium carbonate in pregnancy and children's growth hormone
What it found
In Gambian children whose mothers took calcium carbonate during pregnancy, a growth hormone called IGF1 was higher in boys and lower in girls at about 7.5 years old.
The supplement was taken from 20 weeks of pregnancy to delivery.
What they found
Studies in people
IGF1 in boys
Boys whose mothers took calcium carbonate had higher IGF1 than boys whose mothers took the placebo, by about 14 percent. IGF1 is a hormone that helps drive growth.
IGF1 in girls
Girls whose mothers took calcium carbonate had lower IGF1 than girls whose mothers took the placebo, by about 18 percent.
Sex-specific pattern
The opposite direction of the IGF1 difference in boys and girls was statistically significant, meaning the supplement's link to IGF1 depended on the child's sex.
Other growth markers
Similar patterns were seen for IGFBP3 and for IGF1 adjusted for IGFBP3, but the differences between supplement groups were smaller. There were no significant supplement effects on leptin, insulin, or calcium-related substances.
Body size
Boys whose mothers took calcium carbonate tended to have slightly higher weight and BMI than boys in the placebo group, while girls in the calcium group tended to have slightly lower values. These differences were mostly small and not statistically significant except for BMI in boys.
What the authors conclude
“Calcium carbonate supplementation of pregnant Gambian mothers resulted in higher IGF1 in boys and lower IGF1 in girls during mid-childhood, consistent with the reported maternal supplement effects on growth of the offspring in later childhood.”
Also in their conclusions
- They conclude that calcium carbonate supplementation of pregnant Gambian mothers resulted in higher IGF1 in boys and lower IGF1 in girls during mid-childhood.
- They say this is consistent with the reported maternal supplement effects on growth of the offspring in later childhood.
- They note that longitudinal studies are now in progress to confirm the apparent sex-specific and long-term effects.
How it was done
Earlier work found that children of mothers who took calcium carbonate during pregnancy grew faster if they were boys and slower if they were girls by age 8 to 12. The authors wanted to see if a growth hormone called IGF1, measured earlier in childhood, could help explain those sex-specific growth patterns.
They analysed stored blood samples from 290 children in rural Gambia whose mothers had been randomly assigned to take 1500 mg of calcium per day as calcium carbonate, or a placebo, from 20 weeks of pregnancy to delivery. The children were about 7.5 years old on average when the blood was taken. The researchers measured IGF1 and other growth-related substances and compared boys and girls by their mother's supplement group.
What it can’t tell you
- This study measured IGF1 at one point in childhood, so it cannot show how IGF1 levels changed over time or whether they directly caused the growth differences seen later.
- The children were from a rural Gambian population with low calcium intakes, so the results may not apply to children in other settings with different diets.
- The analysis was planned after the original trial, so it can show links but cannot prove that the supplement alone caused the IGF1 differences.
Who paid
- Funding
- Funded by Medical Research Council (from the PubMed record).
- Conflicts
- Declarations of Interest: None
- Authors work at
- Medical Research Council Elsie Widdowson Laboratory, United Kingdom; Medical Research Council Keneba, The Gambia; University of Southampton, United Kingdom
The paper
- Title
- Pregnancy supplementation of Gambian mothers with calcium carbonate alters mid-childhood IGF1 in a sex-specific manner
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Prentice A, Ward KA, Nigdikar S, Hawkesworth S, Moore SE (2019). Pregnancy supplementation of Gambian mothers with calcium carbonate alters mid-childhood IGF1 in a sex-specific manner. Bone. doi:10.1016/j.bone.2018.11.011Free full textPubMed 30465917DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error